Police said the 50-year-old Canseco was cleaning his handgun and apparently didn’t realize it was loaded.

The gun fired, badly injuring the middle finger on his left hand, authorities said.

Canseco’s fiancée told KTNV-TV the former American League Most Valuable Player had visited a shooting range last week and forgot he left a bullet in the weapon.

Surgeons are trying to determine whether the finger must be amputated, the woman said.

The couple plans to get rid of all their guns, she said.

Canseco hit 462 home runs and drove in 1,407 runs in 17 seasons.

He has admitted to using steroids as a player and claims he personally injected teammates — including Mark McGwire, Rafael Palmeiro, Jason Giambi, Iván Rodríguez, and Juan González — with performance-enhancing drugs.